Abstract: A mattress system offering combinations of comfort and support comprising at least two modules, positioned side-by-side along their longest dimension to define at least two recumbent user areas, and a comfort cushion receivable atop each of the at least two modules. At least one of the modules includes a depression in its upper surface, adapted to removably retain a support insert comprised of an envelope containing a plurality of liquid filled bladders. The mattress system provides an immense array of combinations of firmness and support, allowing each user to adjust, to a very wide degree, the comfort, firmness and support beneath their upper body, lumbar area, and lower body. The adaptable structure of the mattress system also allows the individual user to customize his/her side of the bed and easily change his/her side of the bed as his/her preferences change. Additionally, the construction increases the longevity of the bed, because components may be replaced one at a time as deemed necessary.